Molecular Analysis Of The Function Of A Muscle-specific Caveolar Protein
Funder
National Health and Medical Research Council
Funding Amount
$462,528.00
Summary
Muscular dystrophy is one of the most common and most debilitating inherited diseases in humans. Muscle from patients with muscular dystrophy is highly susceptible to damage leading to muscle wasting. In order to understand muscular dystrophy and to design therapeutic treatments, it is essential that researchers gain a detailed understanding of the workings of the muscle cell surface membrane. Caveolae are small pits which cover the entire surface of the muscle fibre. The major protein of muscle ....Muscular dystrophy is one of the most common and most debilitating inherited diseases in humans. Muscle from patients with muscular dystrophy is highly susceptible to damage leading to muscle wasting. In order to understand muscular dystrophy and to design therapeutic treatments, it is essential that researchers gain a detailed understanding of the workings of the muscle cell surface membrane. Caveolae are small pits which cover the entire surface of the muscle fibre. The major protein of muscle caveolae is caveolin-3, and mutations in this protein cause some forms of muscular dystrophy. This proposal aims to examine the function of this protein using a number of strategies. The caveolin-3 gene will be disrupted in mice to produce mice which lack this protein. The muscle from these mice will then be examined to see what effect the lack of this protein has on muscle function and whether this muscle is similar to that in patients with muscular dystrophy. The muscle from these mice will then be used to design treatments for the disease. In addition, we will search for proteins which work together with caveolin-3 in order to understand how the protein works in healthy and diseased muscle.Read moreRead less
The Role Of Cholesterol In Patched/hedgehog Signalling During Mammalian Development.
Funder
National Health and Medical Research Council
Funding Amount
$198,660.00
Summary
Fluctuations in levels of cholesterol during development of the mammalian embryo have been shown to have catastrophic affects leading to gross deformities particularly in terms of brain and facial development. The requirement of the developing embryo for cholesterol has been linked to the patched-hedgehog signalling pathway which we have previously shown to be central to mammalian development as well as tumour formation. In particular, the patched protein which is responsible for regulating sign ....Fluctuations in levels of cholesterol during development of the mammalian embryo have been shown to have catastrophic affects leading to gross deformities particularly in terms of brain and facial development. The requirement of the developing embryo for cholesterol has been linked to the patched-hedgehog signalling pathway which we have previously shown to be central to mammalian development as well as tumour formation. In particular, the patched protein which is responsible for regulating signalling through this complex cascade of protein interactions has a domain similar to that which in other proteins has been shown to detect and respond to intracellular levels of cholesterol. The patched protein binds to hedgehog at the surface of the cell and mediates the transduction of the the hedgehog signal into the cell. By analogy to the role of sterol sensing domains in other proteins, we hypothesise that this domain in patched detects fluctuations in intracellular cholesterol levels which in turn alter trafficking of patched to the cell surface where it can participate in the hedgehog receptor complex. This hypothesis is supported by our preliminary data which suggests that patched is normally localised both at the cell surface and intracellularly. We are proposing a series of experiments to test our hypothesis, most of which deal with determing the localisation of patched in a cell culure system exposed to agents aimed at varying the intracellular levels of cholesterol. Subcellular localisation of patched will be analysed by immunofluorescence, electron microscopy and immunoblotting analysis. We will also test the ability of patched to aggregate at the cell surface with other molecules important in receiving and sending the hedgehog signal. The experiments in this proposal are likely to give the first clues as to the function of the sterol sensing domain in patched and its role in mediating the vital link between cholesterol and embryonic development.Read moreRead less